Fuel bladder apparatus and method

ABSTRACT

A fuel bladder apparatus includes a fuel bladder, tank, and cap. The fuel bladder includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, inlet port, outlet port, and air inlet. The inlet port is disposed in cooperative alignment with the fuel inlet. The fuel inlet is sealed to the inlet port. The outlet port is disposed in cooperative alignment with the fuel outlet. The cap is detachably secured to the inlet port. The cap detachably seals the fuel inlet.

FIELD OF THE INVENTION

The present invention generally relates to a fuel bladder apparatus and method. More particularly, the present invention pertains to a low permeability fuel bladder to store and provide fuel for an engine and method for storing and providing fuel for an engine.

BACKGROUND OF THE INVENTION

Fuel burning engines are utilized to provide power in a vast array of applications. Generally, a fuel tank is utilized to store and provide a ready supply of fuel for the engine. Typically, the fuel tank is a container with relatively rigid sides of metal or plastic and a cap that is removed to fill the fuel tank. The cap is vented to allow air into the tank. In use, as fuel is drawn out of the tank to be combusted in the engine, the volume of fuel removed is displaced by fuel vapor and air drawn in through the vent in the cap. Without this venting, a partial vacuum may form in the tank and fuel may cease to flow to the engine. Unfortunately, the vented cap also allows fuel vapor to escape into the environment.

To reduce this escape of fuel, some conventional tank systems employ a carbon filter in line with a tank vent to absorb fuel vapors. For example, carbon filters have been utilized in the automotive industry with some success. Compared to the cost of a automobile, the added cost of a carbon filter or vapor recovery system is relative low. However, compared to the cost of most yard equipment, the added cost of a carbon filter may be relatively expensive. In addition, although a carbon filter reduces pollution that results from fuel vapors escaping from the tank out into the environment via permeation or effusion through the wall of the fuel tank, to re-fill the tank, the cap is opened and, as fuel is poured into the fuel tank, the fuel vapor in the tank is displaced by the added volume of fuel and expelled from the inlet.

Accordingly, it is desirable to provide a method and apparatus capable of overcoming the disadvantages described herein at least to some extent.

SUMMARY OF THE INVENTION

The foregoing needs are met, to a great extent, by the present invention, wherein in one respect a fuel bladder to store and provide fuel for an engine and method for storing and providing fuel for an engine is provided.

An embodiment of the present invention pertains to a fuel bladder apparatus. The fuel bladder apparatus includes a fuel bladder, tank, and cap. The fuel bladder includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, inlet port, outlet port, and air inlet. The inlet port is disposed in cooperative alignment with the fuel inlet. The fuel inlet is sealed to the inlet port. The outlet port is disposed in cooperative alignment with the fuel outlet. The cap is detachably secured to the inlet port. The cap detachably seals the fuel inlet.

Another embodiment of the present invention relates to an apparatus for supplying fuel to a yard equipment engine. The apparatus includes a means for disposing a fuel bladder in a tank and means for sealing the fuel inlet to the inlet port to generate a fuel bladder volume and a tank volume. The means for disposing a fuel bladder in a tank includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, an inlet port, outlet port, and air port. The inlet port is disposed in cooperative alignment with the fuel inlet. The outlet port is disposed in cooperative alignment with the fuel outlet. The fuel bladder volume is fluidly isolated from the tank volume. The tank volume is in fluid connection with the atmosphere via the air port. Air from the atmosphere enters the tank volume via the air port in response to fuel being removed from the fuel bladder and air.

Yet another embodiment of the present invention pertains to a method of supplying fuel to a yard equipment engine. In this method a fuel bladder is disposed in a tank. The fuel bladder includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, inlet port, outlet port and air port. The inlet port is disposed in cooperative alignment with the fuel inlet. The outlet port is disposed in cooperative alignment with the fuel outlet. The fuel inlet is sealed to the inlet port to generate a fuel bladder volume and a tank volume. The fuel bladder volume is fluidly isolated from the tank volume. The tank volume is in fluid connection with the atmosphere via the air port. Air from the atmosphere enters the tank volume via the air port in response to fuel being removed from the fuel bladder and air.

There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cut-away side view of a fuel tank and fuel bladder according to an embodiment of the invention and an engine suitable for use with the fuel tank.

FIG. 2 is a cut-away view of the fuel tank and fuel bladder of FIG. 1 in a filled condition.

FIG. 3 is a cut-away view of the fuel tank and fuel bladder of FIG. 1 in a partially filled condition.

FIG. 4 is a cut-away view of the fuel tank and fuel bladder of FIG. 1 in an empty condition.

FIG. 5 is a cut-away view of a fuel tank and fuel bladder according to another embodiment.

FIG. 6 is a partial cut-away view of the fuel tank and fuel bladder according to FIG. 5 in a partially filled condition.

FIG. 7 is a cut-away view of a fuel tank and fuel bladder according to another embodiment.

FIG. 8 is a partial cut-away view of the fuel tank and fuel bladder according to FIG. 7 in a partially filled condition.

DETAILED DESCRIPTION

Preferred embodiments of the invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. As shown in FIG. 1, a power unit 10 includes an engine 12 and a fuel apparatus 14. In a preferred embodiment, the engine 12 is an internal combustion engine that utilizes any suitable fuel such as gas, diesel, and/or other such liquid fuel. In a particular example, the engine 12 is suitable for use to power yard equipment such as a lawn mower, tiller, chipper, snow blower, power washer, or the like. The fuel apparatus 14 is configured to store and/or supply the fuel to the engine 12. In one example of a preferred embodiment, the fuel apparatus 14 includes a fuel bladder 16 and tank 18.

In general, the fuel bladder 16 includes an envelope or container that is compatible with fuel and is impermeable or has a low fuel permeability. In various embodiments, the fuel bladder 16 may include any suitable flexible or elastomeric material. Examples of suitable elastomeric materials includes rubber, poly tetra fluoro ethylene (“PTFE”), poly ether ether ketone (“PEEK”), thermoplastic urethane, and the like. The elastomeric material may be utilized alone or as a coating. In a particular example, the fuel bladder 16 may include a rubber or polymer coated fabric. Rubber or polymer coated fabric may provide improved abrasion resistance as compared to fuel bladders without fabric reinforcement. The fuel bladder 16 includes a fuel inlet 20 and fuel outlet 22. The fuel inlet 20 is configured to receive fuel that is poured or otherwise introduced to the fuel bladder 16. When not actively being filled, the fuel inlet 20 may be sealed via a cap 24. The fuel outlet 22 is disposed to draw fuel out of the fuel bladder 16. In a particular example, the fuel outlet 22 is disposed at a low portion or bottom of the fuel bladder 16.

The tank 18 may be a relatively rigid housing or container to protect the fuel bladder 16, contain leaked fuel in the event of damage to the fuel bladder 16, and/or secure the fuel apparatus 14 to the engine 12. To this end, the tank 18 may be fabricated from any suitable material such as, for example, metal, plastic, or the like. The tank 18 includes an inlet port 26, outlet port 28, and air port 30. The inlet port 26 is secured or affixed to the fuel inlet 20. For example, the inlet port 26 may be secured to the fuel inlet 20 by an adhesive and/or mechanical fastener. The outlet port 28 provides access to the fuel outlet 22 and/or an opening through which a fuel line 32 may fluidly connect the fuel bladder 16 to the engine 12. The air port 30 is configured to facilitate an ingress and egress of air into and out of the tank 18. That is, the air port allows and essentially free exchange of air into and out of the tank 18. It is an advantage of various embodiments of the invention that fuel and fuel vapors are essentially prevented from escaping into the environment during this free exchange of air. That is, due to the fuel bladder 16, the tank 18 is divided into two distinct volumes, for example, a free tank volume 34 and a bladder volume 36. As fuel from the fuel bladder 16 is utilized by the engine 12, the bladder volume 36 is reduced. Air enters the free tank volume 34 via the air port 30 to offset the reduction in the bladder volume 36. Conversely, in response to an increase in the bladder volume 36, air may exit the air port 30. For example, in response to introducing fuel to the fuel bladder 16 via the fuel inlet 20, the bladder volume 36 may increase and the free tank volume 34 may decrease as air exits via the air port 30. In this manner, the air port 30 facilitates an ambient pressure equilibrium in the tank 18 acting upon the fuel bladder 16.

FIG. 2 is a cut-away view of the tank 18 and fuel bladder 16 of FIG. 1 in a filled condition. As shown in FIG. 2, the fuel bladder 16 essentially fills the tank 18 and the free tank volume 34 is relatively small. Also shown in FIG. 2, the air port 30 may include a cover or other such structure to reduce the inflow of contaminants such as, for example, dirt, water, insects, etc. In other examples, the air port 30 may include a filter such as, fabric, fibers, or the like, to reduce the inflow of contaminants into the free tank volume 34.

FIG. 3 is a cut-away view of the tank 18 and fuel bladder 16 of FIG. 1 in a partially filled condition. As shown in FIG. 3, the partially filled fuel bladder 16 occupies relatively less of the tank 18 than the filled fuel bladder 16 shown in FIG. 2. In addition, the free tank volume 34 is relatively greater than shown in FIG. 2. According to another embodiment, the air port 30 may be disposed near or integrated into the inlet port 26. It is an advantage of this embodiment that the cap 24 may partially cover the air port 30 and thereby reduce inflow of contaminants into the free tank volume 34.

FIG. 4 is a cut-away view of the tank 18 and fuel bladder 16 of FIG. 1 in an empty condition. As shown in FIG. 4, the essentially empty fuel bladder 16 occupies relatively less of the tank 18 than the filled or partially filled fuel bladder 16 shown in FIGS. 2 and 3. In addition, the free tank volume 34 is relatively greater than shown in FIGS. 2 and 3. According to another embodiment, the air port 30 may be disposed near or integrated into the inlet port 26. It is an advantage of this embodiment that the cap 24 may partially cover the air port 30 and thereby reduce inflow of contaminants into the free tank volume 34.

FIG. 5 is a cut-away view of a tank 18 and fuel bladder 16 according to another embodiment. As shown in FIG. 5, the inlet port 26 includes an inlet tube 38 that extends into the tank 18. According to this embodiment, the fuel bladder 16 expands and contracts by sliding along this inlet tube. The fuel bladder 16 includes a series of pleats 40, a float 42, and a seal 44.

The pleats 40 facilitate expansion and contraction of the fuel bladder 16. For example, in a manner similar to the pleats in a bellows, the pleats 40 facilitate an orderly and efficient contraction and expansion of the fuel bladder 16.

The float 42 provides buoyancy to the top of the fuel bladder 16 in order to keep the top of the fuel bladder 16 floating above any fuel present in the fuel bladder 16. In this regard, the density of the float 42 is relatively less than that of fuel. For example, the float 42 may include air, foam, or the like.

The seal 44 is disposed at an interface between the inlet tube 38 and the float 42. The seal 44 translates along the inlet tube 38. The seal 44 may provide a substantially fuel impermeable or fuel resistant interface to reduce leakage of fuel from the fuel bladder 16 into the free tank volume 34 and/or out of the tank 18.

The fuel bladder 16 shown in FIG. 5 is essentially full of fuel, for example. Accordingly, the free tank volume 34 is relatively small. As shown in FIG. 6, the fuel bladder 16 is substantially empty. As such, the pleats 40 are shown in a relatively compressed state, the bladder volume 36 is relatively low, and the free tank volume 34 is relatively high.

FIG. 7 is a cut-away view of a tank 18 and fuel bladder 16 according to another embodiment. As shown in FIG. 7, the fuel apparatus 14 may be curved, rounded, or the like. In a particular example, the tank 18 may include a clamshell or clamshell-like shape and the fuel bladder 16 may be configured to substantially fill the tank 18 when full. It is an advantage of this embodiment that the fuel bladder 16 collapses or “pancakes” down upon itself readily. As such, the fuel bladder 16 may modulate according to the bladder volume 36 without the need for pleats.

In addition, the fuel apparatus 14 optionally includes a gasket 46 to seal the fuel inlet 20 and/or the inlet port 26. If present, the gasket 46 may include an elastomeric material disposed between the cap 24 and the fuel inlet 20 and/or the inlet port 26, for example. In a particular example, the gasket 46 maybe affixed to the underside of the cap 24 and configured to engage the inlet port 26 in response to securing the cap 24 to the inlet port 26.

FIG. 8 is a partial cut-away view of the tank 18 and fuel bladder 16 according to FIG. 7 in an essentially empty condition. As shown in FIG. 8, the fuel bladder 16 essentially collapses upon itself in an efficient manner. As such, substantially all or most of the fuel from the fuel bladder 16 may be utilized by the engine 12 shown in FIG. 1. In addition, the fuel bladder 16 readily expands in response to the addition of fuel e.g., by pouring fuel into the fuel inlet 20.

The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 

1. A fuel bladder apparatus comprising: a fuel bladder comprising: an elastomeric envelope having an upper section, lower section and side section; a fuel inlet disposed at the upper section; a fuel outlet disposed at the lower section; a tank comprising: a rigid housing; an inlet port disposed in cooperative alignment with the fuel inlet, wherein the fuel inlet is sealed to the inlet port; an outlet port disposed in cooperative alignment with the fuel outlet; and an air inlet; and a cap detachably secured to the inlet port, wherein the cap detachably seals the fuel inlet.
 2. The fuel bladder apparatus according to claim 1, wherein the elastomeric envelope comprises a rubberized fabric.
 3. The fuel bladder apparatus according to claim 1, wherein the elastomeric envelope comprises a rubberized fabric.
 4. The fuel bladder apparatus according to claim 1, wherein the elastomeric envelope includes poly tetra fluoro ethylene.
 5. The fuel bladder apparatus according to claim 1, wherein the elastomeric envelope includes poly ether ether ketone.
 6. The fuel bladder apparatus according to claim 1, wherein the elastomeric envelope includes thermoplastic urethane.
 7. The fuel bladder apparatus according to claim 1, further comprising: a tube extending inwardly with respect to the inlet port; a float secured to the upper section of the elastomeric envelope; and a seal configured to slidably engage the tube, the seal being secured to the float.
 8. The fuel bladder apparatus according to claim 1, further comprising: a series of pleats along the side section.
 9. The fuel bladder apparatus according to claim 1, further comprising: a filter disposed within the air inlet..
 10. An apparatus for supplying fuel to a yard equipment engine, the apparatus comprising: means for disposing a fuel bladder in a tank, the fuel bladder comprising: an elastomeric envelope having an upper section, lower section and side section; a fuel inlet disposed at the upper section; a fuel outlet disposed at the lower section; the tank comprising: a rigid housing; an inlet port disposed in cooperative alignment with the fuel inlet; an outlet port disposed in cooperative alignment with the fuel outlet; and an air port; and means for sealing the fuel inlet to the inlet port to generate a fuel bladder volume and a tank volume, the fuel bladder volume being fluidly isolated from the tank volume, the tank volume being in fluid connection with the atmosphere via the air port, wherein air from the atmosphere enters the tank volume via the air port in response to fuel being removed from the fuel bladder and air.
 11. The apparatus according to claim 10, further comprising: means for threading a fuel line through the outlet port, wherein the fuel line is in fluid connection with the fuel outlet.
 12. The apparatus according to claim 11, further comprising: means for fluidly connecting the fuel line to the engine.
 13. The apparatus according to claim 10, further comprising: means for slidably sealing the fuel inlet to a tube extending inwardly from the inlet port.
 14. The apparatus according to claim 10, further comprising: means for pleating the elastomeric envelope.
 15. The apparatus according to claim 10, further comprising: means for filtering air passing through the air port.
 16. A method of supplying fuel to a yard equipment engine, the method comprising: disposing a fuel bladder in a tank, the fuel bladder comprising: an elastomeric envelope having an upper section, lower section and side section; a fuel inlet disposed at the upper section; a fuel outlet disposed at the lower section; the tank comprising: a rigid housing; an inlet port disposed in cooperative alignment with the fuel inlet; an outlet port disposed in cooperative alignment with the fuel outlet; and an air port; and sealing the fuel inlet to the inlet port to generate a fuel bladder volume and a tank volume, the fuel bladder volume being fluidly isolated from the tank volume, the tank volume being in fluid connection with the atmosphere via the air port, wherein air from the atmosphere enters the tank volume via the air port in response to fuel being removed from the fuel bladder and air.
 17. The method according to claim 16, further comprising: threading a fuel line through the outlet port, wherein the fuel line is in fluid connection with the fuel outlet.
 18. The method according to claim 17, further comprising: fluidly connecting the fuel line to the engine.
 19. The method according to claim 16, further comprising: slidably sealing the fuel inlet to a tube extending inwardly from the inlet port.
 20. The method according to claim 16, further comprising: pleating the elastomeric envelope.
 21. The method according to claim 16, further comprising: filtering air passing through the air port. 